Why is StreamWriter not working?

[shockna1]

Im trying to write a class to replace strings in a text file but for some reason StreamWriter will not work in my class. Its not throwing any exceptions or anything its just not writing to the text file. Also I used to have a destructor in my class but it was throwing an exception when I tried to close or dispose outFile.

class TextReplacer
{
    private StreamReader inFile;
    private StreamWriter outFile;
 
    public TextReplacer(StreamReader _in, StreamWriter _out)
    {
        inFile = _in;
        outFile = _out;
 
        outFile.WriteLine("TESTING!!!"); // DOES NOT WORK
    }
 
    public void Repace(string find, string replace)
    {
        string line = inFile.ReadLine();
 
        if (line != null)
        {
            line = line.Replace(find, replace);
 
            Console.WriteLine(line);
 
            outFile.WriteLine(line); // DOES NOT WORK
 
            Repace(find, replace);
        }
 
        return;
    }
}
 

[Aimee Bailey]

I'm betting this is probably because you still have the file open in read-only mode. A quick way to do what your trying to do could be:

public void ReplaceInFile(string file, string find, string replace)
{
    string buffer = File.ReadAllText(file);
    buffer = buffer.Replace(find, replace);
    File.WriteAllText(file, buffer);
}
 

However if you needed to use StreamReader and StreamWriter within a class, then this is probably what your looking for:

public void Replace(string find, string replace)
{
    string buffer = "";
    using(FileStream fs = new FileStream(m_Filename, FileMode.OpenOrCreate, FileAccess.ReadWrite))
    {
        StreamReader sr = new StreamReader(fs);
        buffer = sr.ReadToEnd();
 
        buffer = buffer.Replace(find, replace);
 
        fs.Position = 0;
 
        using(StreamWriter sw = new StreamWriter(fs))
        {
            sw.Write(buffer);
            sw.Flush();
            sw.Close();
            sr = null;
        }
    }    
}
 

All the best.

Aimee.